The United Nations Security Council has ordered the end of the UN observer mission in Syria but backed calls for a civilian office to remain in Damascus.

France's UN Ambassador Gerard Araud, the current Security Council president, said the move came after a council meeting on August 16 on the Syrian conflict.

"The mandate of [the UN Syria observer mission] is over on the 19th of August, so if you don't renew the mandate of [the UN Syria observer mission], the mandate is over. The dismantling of [the UN Syria observer mission] will start in a few days," Araud said.

Araud said the conditions for extending the mission, which ends at midnight on August 19, were not met. He said there had been little progress in halting escalating violence and convincing Syrian President Bashar al-Assad's regime to stop its use of heavy weapons on the civilian population.

Russian Ambassador to the UN Vitaly Churkin, speaking to journalists at the UN in New York, said he regretted the UN mandate was coming to an end.

"We believe that those members of the council who insisted that [the UN Syria observer mission] can't continue did not really show a commitment to ending hostilities and to working toward a political settlement in Syria," Churkin said.

Although the unarmed military observers will leave Damascus over the next few days, a civilian liaison office will remain to monitor events.

Earlier on August 16, Syrian state media slammed a decision by the Organization of Islamic Cooperation (OIC) to suspend the country's membership, saying the body supported "Western colonialism" and its members backed "terrorists."

The OIC announced it had suspended Syria's membership of the 57-nation body at the end of an emergency meeting on August 16 in Mecca, where members expressed "deep concern at the massacres and inhuman acts suffered by the Syrian people."